Process of manufacturing smokeless powder



atented Dec. 13, 1932 men WEINGAND AND HANS ISAAC SCHULZ, on BoMLr'rz NEAR WALSRODE,

' GERMANY PROCESS OF MANUFACTURING SMOKELESS POWD'ER No Drawing. Application filed march 25, 1931, Serial No. 525,328, and in Germany March 28, 1980.

This invention has reference to smokeless powder, and it is intended among other important objects and advantages to facilitate the gelatinization of the nitrocellulose which forms the chief constituent of the powder and to increase and improve the yield and the condition of marketable material. In the manufacture of smokeless powder by the gelatinization of a mixtureof so-called gun-cotton or shooting wool and collodium wool with ether-alcohol as heretofore practiced part of the operative driving energy obtainable by the use of pure shooting wool is sacrifi'ced and lost by the addition of collodium wool which possesses less driving energy, in order to be able to carry into effect the gelatinization-by means of ether-alcohol. Pure gun-cotton cannot be gelatinized by ether-alcohol and the other solvents such as for instance acetone, \acetic ether, butyl-acetate which possess gelatinizing properties can only be removed from the powder with difiiculty and their presence renders the powder unstable.

Now it has been ascertained in the course of our experiments that gelatinization of nitrocellulose with a high content of nitrogen may be obtained at ordinary temperature by causing the gelatinization of nitrocellulose ing wool. without the addition of collodium and at ordinary temperature into gelatinized homogeneous kinds of powder of satisfactory .cohering properties merely by the use of corresponding pressures, while at ordinary atmospheric pressure such powder material is devoid of coherence even When carefully mixed as distinguished from the ordinary mixtures which contain collodium, and

which at this pressure are already gelatinized.

By operating in this manner it is possible to' obtain smokeless powders with a content of 13.6 per cent of nitrogen and possessing a correspondingly high energy without ditliculty. To the mixture of nitrocellulose and organic liquid the customary additions employed in the manufacture of powder may be made, such as plasticizers, stabilizers and similar substances.

It has already been proposed to convert nitrocellulose into a very fluid solution for the purpose .ofremoving mechanical impurities therefrom by the use of a considerable excess of the solvent, this solution being then forced through filtering cotton. In this case the nitrocellulose is dissolved, when submitted to the action of pressure, while in accordance with our invention the gelatinization of the nitrocellulose is effected under pressure. It is well known moreover to utilize pressure for the purpose of shaping the nitrocellulose after the previous gelatinization thereof by means of nitroglycerine or by any other agent which produces gelatinization at the ordinary conditions of temperature and pressure. In accordance with the invention submitted however organic liquids are employed which are devoid of gelatinizing properties under ordinary conditions, and which only become active as gelatinizing agents by the use of pressure. It is possible thereby to effect the gelatinization of pure gun cotton with a high content of nitrogen of more than 13 per cent by means of inexpensive organic liquids, such as methanol and by a liquid mixture containing methanol, methanol-ether and the like.

Ewamplc.150 kilograms of methanoltreatcd gun cotton (shooting wool) containing 100 kilograms gun-cotton with 13.3% nitrogen and 50 kg. methanol are agitated with kg. diethyl-ether in a mixer for 30 minutes with a view of uniform distribution of the solvent. whereupon the somewhat flufiy mass is introduced into the pressing pots of a hydraulic press and is exposed to a pressure of 200 atmospheres and is formed into strings or strands of powder by correspondingly shaped dies. These strings, rods or the like may then be manufactured into laminar or tubular powder in the usual manner, and if necessary, may be submitted to the ordinary after-treatment.

It should, of course, be understood that the.

5 invention is not limited to the particular exemplification of treatment, herein described, particularly as regards the nature and proportions of the materials employed, the time of treatment and the pressure employed, and

that these and other conditions may be altered in accordance with varying requirements and without thereby deviating from the principles of the invention as expressed in the appended claims' We claim 1. The process of manufacturing smokeless powder which comprises submitting nitrocellulose containing at least 12.8 per cent nitrogen to more than 100 atmospheres pressure in the resence of volatile organic liquids incapab e of producing gelatinization at ordinary pressure and thereby gelatinizing the nitrocellulose.

2. The process of manufacturing smokeless powder which comprises submitting nitrocellulose with a content of at least 12.8 per cent nitrogen in presence of Volatile organic liquids to pressure of at least 100 atmospheres and shaping the resulting product; said liquids being incapable of gelatinization of n1- trocellulose at ordinary pressure and temperatures.

3. The process of manufacturing smokeless powder which comprises submitting a mixture of gun-cotton and methanol-containing organic liquids to a pressure of at least 100 atmospheres, thereby causing gelatinization of the mixture, and shaping and comminuting the resulting product.

In testimony whereof we afiix our signatures.

RICHARD WEINGAND. HANS ISAAC SCHULZ. 

